Heredity and Evolution

Where are the genes located? What is the chemical nature of genes?

Define evolution. Describe the contribution of Lamarck.

What is a gene?

In human beings, the statistical probability of getting either a male or female child is 50 : 50. Give a suitable explanation.

A man with blood group A marries a woman with blood O and their daughter has blood group O. Is this information enough to tell you which of the traits  blood group A or O is dominant ? Why or why not ?

Give an example of characteristics being used to determine how close two species am in evolutionary terms ?

How do homologous organs provide evidence in support of evolution?

State whether the following statement is true or false :
The sex of an infant is not a case of inheritance of characteristics.

A new born child has an XY pair of chromosmes. Will it be a baby boy or a baby girl ?

Name five varieties of vegetables which have been produced from ‘wild cabbage’ by the process of artificial selection.

How do Mendel’s experiments show that traits may be dominant or recessive ?

How do Mendel’s experiments show that traits are inherited independently ?

What are the different ways in which individuals with a particular trait may increase in a population ?

Will geographical isolation be a major factor in the speciation of a self-pollinating plant species ? Why or why not ?

In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a ‘better body design’ why or why not ?

A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?

Explain the terms analogous and homologous organs with examples.

What evidence do we have for the origin of life from inanimate matter?

Explain how sexual reproduction gives rise to more viable variations that asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually ?

Define a gene.

What are the components of the chromosome?

What is a sex chromosome?

Define homologous organs.

Define Genetics. What is the contribution of Mendel in the field of genetics?

What do you understand by the double helical structure of DNA? Who proposed this structure?

What is meant by analogous organs? Taking a suitable example, explain how they support the theory of Organic Evolution.

With the help of suitable examples explain natural selection. [Foreign]

What evidence do we have for the origin of life from inanimate matter? [All India]

Explain with examples how the following are evidences in favour of evolution in organisms.  (i) Homologous organs (ii) Analogous organs (iii) Fossils [Delhi]

What is meant by the term speciation? List four factors which could lead to speciation. [Delhi]

A blue colour flower plant denoted by BB is cross bred with that of white colour flower plant denoted by bb.
(a) State the colour of flower you would expect in their F₁   generation plants.
(b) What must be the percentage of white flower plants in F₂   generation if flowers of  F₁  plants are self-pollinated?
(c) State the expected ratio of the genotypes BB and Bb in the F₂  progeny. [Delhi]

Distinguish between homologous organs and analogous organs. In which category ; would you place wings of a bird and wings of a bat? Justify your answer giving a suitable reason.[Delhi]

State the meaning of inherited traits and acquired traits. Which of the two is not passed on to the next generation? Explain with the help of an example.

What are the chromosomes XY and XX known as ?

What type of plants were used by Mendel for conducting his experiments on inheritance ?

The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a person if he inherits a gene for red hair from his mother and a gene for black hair from his father ?

Name one reptile in each case where higher incubation temperature leads to the development of : (a) male progeny, (b) female progeny.

(a) State one advantage of variation to a species.
(b) What are sex chromosomes ? How many sex chromosomes are there ? Name them.

In a human, how many chromosmes are present in :
(a) a brain cell ?
(b) a sperm in the testes ?
(c) an egg which has just been produced by the ovary ?
(d) a skin cell ?
(e) a fertilised egg ?

(a) What are genes ? Where are they located in our body ?(a) What are genes ? Where are they located in our body ?
(b) What is meant by dominant genes and recessive genes ? Give one example of each.
(c) Explain how, characteristics (or traits) are inherited through genes.

What name is given to the sequence of gradual changes over millions of years in which new species are produced ?

Write the names of at least three inorganic molecules which helped in the origin of life on the earth.

The forelimbs of a frog, a bird and a man show the same basic design (or basic structure) of bones. What name is given to such organs ?

Out of the wing of a bird, wing of an insect and the wing of a bat :
(a) which two are homologous organs ?
(b) which two are analogous organs ?

Choose the one term from the following which includes the other three :
broccoli, wild cabbage, cauliflower, cabbage

Why are the traits acquired during the lifetime of an individual not inherited ?

Give an example of characteristics being used to determine how close two species are in evolutionary terms.

Name the various tools of tracing evolutionary relationships which have been used for studying human evolution.

(a) What is meant by a species ? Give two examples of plant species and two of animals.
(b) State the various factors which could lead to the formation of new species.

(a) Define ‘speciation’. Explain how speciation occurs.
(b) Will geographical isolation be a major factor in the speciation of a self-pollinating plant species ? Give reason for your answer.